Workspace setup

Installing Rust
The recommended method for installing Rust is via rustup, a command-line tool for installing the Rust toolchain and keeping it up to date. It also allows adding useful components and targets for cross-compilation.

If you use a package manager, it's likely that rustup is available as a package. For example, rustup is available as a community package in pacman and in the official NixPkgs Nix repository.

Language servers
Language servers provide code completion, detect errors prior to compilation, and do many other useful things. By using the Language Server Protocol, they are compatible with a wide range of IDEs and editors. The following popular language servers exist for Rust:

On the fly checking using both RLS and rust-analyzer
Currently, rust-analyzer (RA) doesn't support on the fly checking, but it's possible to install both RLS and RA, using the former for on-the-fly checking and the latter for everything else. Since both provide autocompletion, remember to disable racer for RLS in order to prevent any conflicts.

Note that this is a temporary solution and not recommended, although there is no harm in trying it if you need both RA and live diagnostics, and don't mind the increased memory usage.

Neovim
A full article on how to setup neovim for rust can be found here: https://sharksforarms.dev/posts/neovim-rust/